The Hero Is Overpowered But Overly Cautious, Vol. 2 (manga)

The continuing misadventures of Seiya, the absurdly overcautious hero who tried to buy a thousand bottles of holy water as soon as he knew he'd be fighting undead, and Rista, a goddess who's always waving her "literally holier than thou" attitude in his face. Things start off badly when Seiya immediately butts heads with the Dragonkin who were supposed to become his allies-and does he have a plan for dealing with the army of ten-thousand undead approaching the town.